This section describes the background of the disclosed embodiments of the present invention. There is no intention, either express or implied, that the background art discussed in this section legally constitutes prior art.
Light sources are typically used to illuminate or to attract attention. For example, a flashlight provides illumination and traffic signals and automobile tail lights are designed to be easily visible. These displays are typically switched completely on or off. It would be desirable to make these and other light sources more visible by presenting a dynamic, changing display rather than a fully-on display. The increase in visibility for a tail-light or traffic signal provides two benefits—it is more attention-getting and therefore safer, and a dynamic changing display can reduce power since all display elements are not illuminated at the same time. A flashlight can be made safer for anyone walking at night using a flashlight, because while providing illumination for the user, it also provides a moving, and therefore more visible display, for oncoming traffic.
Light sources that present changing patterns are known, for example U.S. Pat. No. 6,206,537 to Hauck periodically changes the color of a moving light source to give the effect of colored light bars in the air. Also, flashlights built from solid-state emitters, such as light emitting diodes (LEDs), are popular due to the availability of efficient and very bright white LEDs. Some of these flashlights have different switchable intensity settings, where different overall intensities are accomplished by simultaneously powering varying numbers of LEDs.
APPENDIX A is a program listing for one example implementation of the Animated light source.
APPENDIX B shows the correspondence between L-variables in the APPENDIX A listing and LED positions.